Journal ArticleDOI
Biomineralization mechanism of gold by zygomycete fungi Rhizopus oryzae.
TLDR
The biosynthesis mechanism of gold nanoparticles (AuNPs) in the fungus Rhizopus oryzae is described, showing that at higher Au(III) concentrations, both mycelial and protein yield decrease and damages to the cellular ultrastructure are observed, likely due to the toxic effect of Au( III).Abstract:
In recent years, there has been significant progress in the biological synthesis of nanomaterials. However, the molecular mechanism of gold biomineralization in microorganisms of industrial relevance remains largely unexplored. Here we describe the biosynthesis mechanism of gold nanoparticles (AuNPs) in the fungus Rhizopus oryzae . Reduction of AuCl(4)(-) [Au(III)] to nanoparticulate Au(0) (AuNPs) occurs in both the cell wall and cytoplasmic region of R. oryzae . The average size of the as-synthesized AuNPs is ~15 nm. The biomineralization occurs through adsorption, initial reduction to Au(I), followed by complexation [Au(I) complexes], and final reduction to Au(0). Subtoxic concentrations (up to 130 μM) of AuCl(4)(-) in the growth medium increase growth of R. oryzae and induce two stress response proteins while simultaneously down-regulating two other proteins. The induction increases mycelial growth, protein yield, and AuNP biosynthesis. At higher Au(III) concentrations (>130 μM), both mycelial and protein yield decrease and damages to the cellular ultrastructure are observed, likely due to the toxic effect of Au(III). Protein profile analysis also confirms the gold toxicity on R. oryzae at high concentrations. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis shows that two proteins of 45 and 42 kDa participate in gold reduction, while an 80 kDa protein serves as a capping agent in AuNP biosynthesis.read more
Citations
More filters
Journal ArticleDOI
Engineering tailored nanoparticles with microbes: quo vadis?
TL;DR: This Focus Review critically review the advances in nanoparticle synthesis using microbes, and discusses new insights into the cellular mechanisms of such formation that may, in the near future, allow complete control over particle morphology and functionalization.
Journal ArticleDOI
Bio-inspired synthesis of metal nanomaterials and applications
TL;DR: This critical review focuses on recent advances in the bio-inspired synthesis of metal nanomaterials using microorganisms, viruses, plants, proteins and DNA molecules as well as their applications in various fields.
Journal ArticleDOI
Fungal biosynthesis of gold nanoparticles: mechanism and scale up
TL;DR: The known mechanisms for Au NP biosynthesis in viable fungi and fungal protein extracts are described and the most suitable bioreactors for industrial AuNP biosynthesis are discussed.
Journal ArticleDOI
Fabrication of Metal Nanoparticles from Fungi and Metal Salts: Scope and Application
TL;DR: This review focuses on the biogenic synthesis of metal nanoparticles by fungi to explore the chemistry of their formation extracellularly and intracellularly.
Journal ArticleDOI
Sunlight-Induced Reduction of Ionic Ag and Au to Metallic Nanoparticles by Dissolved Organic Matter
TL;DR: It is shown that dissolved organic matter (DOM) in environmental waters can mediate the reduction of ionic Ag and Au to their metallic nanoparticles under natural sunlight, suggesting that this process may be general for metals with high reduction potential.
References
More filters
Book
Green Chemistry: Theory and Practice
Paul T. Anastas,John C. Warner +1 more
TL;DR: Green Chemistry: What is green chemistry? as discussed by the authors presents the principles of green chemistry and evaluates the impact of chemistry on the environment. But, it is not a complete overview of all of the issues involved in green chemistry.
Journal ArticleDOI
Protein-directed synthesis of highly fluorescent gold nanoclusters.
TL;DR: A simple, one-pot, "green" synthetic route, based on the "biomineralization" capability of a common commercially available protein, bovine serum albumin (BSA), has been developed for the preparation of highly stable Au nanocrystals (NCs) with red emission and high quantum yield.
Journal ArticleDOI
Shape Control of Colloidal Metal Nanocrystals
TL;DR: In this paper, an overall picture of shaped metal particles is presented, with a particular focus on solution-based syntheses for the noble metals, emphasizing key factors that result in anisotropic, nonspherical growth such as crystallographically selective adsorbates and seeding processes.
Journal ArticleDOI
Higher-order organization by mesoscale self-assembly and transformation of hybrid nanostructures
Helmut Cölfen,Stephen Mann +1 more
TL;DR: This work highlights how the interplay between aggregation and crystallization can give rise to mesoscale self-assembly and cooperative transformation and reorganization of hybrid inorganic-organic building blocks to produce single-crystal mosaics, nanoparticle arrays, and emergent nanostructures with complex form and hierarchy.
Journal ArticleDOI
Shewanella secretes flavins that mediate extracellular electron transfer
Enrico Marsili,Daniel B. Baron,Indraneel D. Shikhare,Dan Coursolle,Jeffrey A. Gralnick,Daniel R. Bond +5 more
TL;DR: In situ demonstration of flavin production, and sequestration at surfaces, requires the paradigm of soluble redox shuttles in geochemistry to be adjusted to include binding and modification of surfaces.